JP2013227361A - Aqueous resin composition and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous resin composition which is excellent in resistance to hot water whitening, resistance to freeze and thawing and blocking resistance in a comprehensive manner.SOLUTION: An aqueous resin composition contains an emulsion particle having an inner layer and an outer layer. The inner layer is formed from a polymer (I) obtained by emulsion-polymerizing a monomer component containing 5-50 wt.% of a polyfunctional monomer and 50-95 wt.% of a monomer copolymerizable with the polyfunctional monomer, and the outer layer is formed from a polymer (II) having a glass transition temperature of 40°C or lower. The weight ratio [polymer (I)/polymer (II)] of the polymer (I) to the polymer (II) is 25/75 to 75/25, and the total content of the polymer (I) and polymer (II) in the emulsion particle is 50-100 wt.%.

Description

  The present invention relates to an aqueous resin composition and a method for producing the same. More specifically, the present invention relates to an aqueous resin composition useful for, for example, top coating materials and sealers used for building exteriors and ceramic building materials, and a method for producing the same. The water-based resin composition of the present invention can be suitably used for, for example, a top coat material (water-based paint) and a sealer called a top coat which are coated on the surface of a building exterior or a ceramic building material.

  In recent years, in order to avoid environmental problems due to the release of volatile organic compounds into the atmosphere, water-based paints using water-dispersed resins such as water-soluble resins and emulsions have been used in place of solvent-based paints. . However, in contrast to organic solvent-based paints, water-based paints are generally inferior in the durability and appearance of paint films such as drying, water resistance, and weather resistance due to the use of water as a solvent. There is a technical problem that it is difficult to increase the coating film hardness.

  Accordingly, an aqueous coating composition containing two resin components having different glass transition temperatures in a specific ratio as an aqueous coating composition having enhanced coating film hardness and good coating film appearance and durability (for example, patent documents) 1), an aqueous coating composition excellent in weather resistance, water resistance, discoloration resistance, crack resistance, polymerization stability, storage stability, warm water resistance, film-forming property, temperature resistance resistance and coating film appearance. An aqueous coating composition in which multilayer structure particles having a core part and a shell part made of an acrylic polymer having a specific glass transition temperature are dispersed in water has been proposed (for example, see Patent Document 2).

  However, each of the water-based coating compositions has a disadvantage that it is inferior in freeze-thaw resistance because it is necessary to increase the glass transition temperature of the shell portion of the particles in order to impart blocking resistance.

  Therefore, in order to improve the blocking resistance, it is conceivable to use a water-soluble polymer having a high glass transition temperature and a low molecular weight, or increasing the pigment content. However, when a water-soluble polymer having a high glass transition temperature and a low molecular weight is used, there is a disadvantage that it is inferior in freeze-thaw resistance and the like, and when the pigment content is increased, the film forming property is lowered. As a result, the freeze-thaw resistance is reduced.

JP 2001-200181 A Japanese Patent Laid-Open No. 2002-12816

  This invention is made | formed in view of the said prior art, and makes it a subject to provide the aqueous resin composition and aqueous coating material which were comprehensively excellent in warm water whitening resistance, freeze-thaw resistance, and blocking resistance. .

The present invention
(1) An aqueous resin composition containing emulsion particles having an inner layer and an outer layer, wherein the inner layer is 5 to 50% by weight of a polyfunctional monomer and a monomer copolymerizable with the polyfunctional monomer Formed of a polymer (I) obtained by emulsion polymerization of a monomer component containing 50 to 95% by weight, and the outer layer is formed of a polymer (II) having a glass transition temperature of 40 ° C. or less. The weight ratio of the polymer (I) to the polymer (II) [polymer (I) / polymer (II)] is 25/75 to 75/25, and the polymer (I) and the polymer in the emulsion particles An aqueous resin composition having a total content of (II) of 50 to 100% by weight,
(2) The aqueous resin composition according to (1), wherein the glass transition temperature of the polymer (I) is 70 ° C. or higher,
(3) The aqueous resin according to (1) or (2), wherein the monomer component used in the polymer (I) has a glass transition temperature of 80 ° C. or more and the content of the monomer is 80% by weight or more. Composition,
(4) The aqueous resin composition according to any one of (1) to (3), which has a minimum film-forming temperature of 60 ° C. or less,
(5) The content of the carboxyl group-containing monomer in the monomer component used in the polymer (II) is more than the content of the carboxyl group-containing monomer in the monomer component used in the polymer (I). The aqueous resin composition according to any one of (1) to (4),
(6) A method for producing an aqueous resin composition comprising an aqueous paint comprising the aqueous resin composition according to any one of (1) to (5), and (7) an emulsion particle having an inner layer and an outer layer. A monomer component containing 50 to 95% by weight of a polyfunctional monomer and 5 to 50% by weight of a monomer copolymerizable with the polyfunctional monomer is emulsion-polymerized, and the resulting weight is obtained. After forming the inner layer made of the polymer (I), the weight of the polymer (I) and the polymer (II) when forming the outer layer made of the polymer (II) having a glass transition temperature of 40 ° C. or lower. The ratio [polymer (I) / polymer (II)] was adjusted to 25/75 to 75/25, and the content of polymer (I) and polymer (II) in the emulsion particles was 50 to 100% by weight. It is related with the manufacturing method of the aqueous resin composition characterized by adjusting so that it may become.

  ADVANTAGE OF THE INVENTION According to this invention, the water-based resin composition and water-based coating material which were comprehensively excellent in hot water whitening resistance, freeze-thaw resistance, and blocking resistance are provided.

  As described above, the aqueous resin composition of the present invention is an aqueous resin composition containing emulsion particles having an inner layer and an outer layer.

  In the aqueous resin composition of the present invention, the inner layer contains 5 to 50% by weight of a polyfunctional monomer and 50 to 95% by weight of a monomer copolymerizable with the polyfunctional monomer. Formed of polymer (I) obtained by emulsion polymerization of the components, and the outer layer is formed of polymer (II) having a glass transition temperature of 40 ° C. or less, and polymer (I) and polymer (II) ) [Polymer (I) / polymer (II)] is 25/75 to 75/25, and the total content of the polymer (I) and the polymer (II) in the emulsion particles is 50 to 100% by weight.

  In the present invention, for example, by emulsion polymerization of a monomer component containing 5 to 50% by weight of a polyfunctional monomer and 50 to 95% by weight of a monomer copolymerizable with the polyfunctional monomer. After preparing the inner layer made of polymer (I), emulsion particles having inner and outer layers are contained by emulsion polymerization of the monomer component forming polymer (II) having a glass transition temperature of 40 ° C. or lower A resin emulsion is prepared, and the obtained resin emulsion can be used as an aqueous resin composition.

  Hereinafter, a monomer component used as a raw material for the polymer (I) is referred to as a monomer component A, and a monomer component used as a raw material for the polymer (II) is referred to as a monomer component B.

  In the present invention, a layer other than the inner layer and the outer layer may be formed in the emulsion particles as long as the object of the present invention is not impaired. Therefore, a layer other than the inner layer may be formed inside the inner layer, or a layer other than the outer layer may be formed outside the outer layer, as long as the object of the present invention is not hindered.

  The polymer (I) forming the inner layer is a monomer component A containing 5 to 50% by weight of a polyfunctional monomer and 50 to 95% by weight of a monomer copolymerizable with the polyfunctional monomer. Can be obtained by emulsion polymerization.

  Examples of the polyfunctional monomer include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, ethylene oxide modified 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, propylene oxide modified neopentyl glycol di (meth) acrylate, Di (meth) acrylate of polyhydric alcohol having 1 to 10 carbon atoms such as tripropylene glycol di (meth) acrylate; polyethylene glycol di (meth) acrylate having 2 to 50 addition moles of ethylene oxide, addition moles of propylene oxide 2 An alkyl di (meth) acrylate having an addition mole number of an alkylene oxide group having 2 to 4 carbon atoms such as 50 polypropylene glycol di (meth) acrylate and tripropylene glycol di (meth) acrylate; ethoxylated glycerin tri ( (Meth) acrylate, propylene oxide modified glycerol tri (meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol monohydroxytri (meth) acrylate, trimethylolpropane triethoxytri Tri (meth) acrylates of polyhydric alcohols having 1 to 10 carbon atoms such as (meth) acrylate; pentaerythritol tetra (meth) acrylate, dipentaeri Tetra (meth) acrylates of polyhydric alcohols having 1 to 10 carbon atoms such as lithol tetra (meth) acrylate and ditrimethylolpropane tetra (meth) acrylate; pentaerythritol penta (meth) acrylate, dipentaerythritol (monohydroxy) penta (meth) ) Penta (meth) acrylate of polyhydric alcohol having 1 to 10 carbon atoms such as acrylate; Hexa (meth) acrylate of polyhydric alcohol having 1 to 10 carbon atoms such as pentaerythritol hexa (meth) acrylate; Bisphenol A di (meth) ) Acrylate, 2- (2′-vinyloxyethoxyethyl) (meth) acrylate, epoxy group-containing (meth) acrylates such as epoxy (meth) acrylate; polyfunctional (meth) acrylates such as urethane (meth) acrylate Examples include chlorate, but the present invention is not limited to such examples. These polyfunctional monomers may be used alone or in combination of two or more.

  Among polyfunctional monomers, from the viewpoint of improving warm water whitening resistance, freeze-thaw resistance, and blocking resistance, alkyl di (meth) acrylates having 2 to 8 alkyl groups and 4 to 8 carbon atoms, ethylene oxide Of polyethylene glycol di (meth) acrylate having an addition mole number of 2 to 50, polypropylene glycol di (meth) acrylate having an addition mole number of propylene oxide of 2 to 50, tri (meth) acrylate of polyhydric alcohol, polyhydric alcohol Preferred are tetra (meth) acrylate, penta (meth) acrylate of polyhydric alcohol, and hexa (meth) acrylate of polyhydric alcohol, and ethylene glycol di (meth) acrylate and polyethylene glycol di (2) having an ethylene oxide addition mole number of 2-50. (Meth) acrylate, 1 4-butanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, and ditrimethylolpropane tetra (meth) acrylate are more preferred.

  In the present specification, “(meth) acrylate” means “acrylate” or “methacrylate”, and “(meth) acryl” means “acryl” or “methacryl”.

  The content of the polyfunctional monomer in the monomer component A is 5% by weight from the viewpoint of obtaining a water-based resin composition and a water-based paint which are comprehensively excellent in hot water whitening resistance, freeze-thaw resistance and blocking resistance. Above, preferably 7% by weight or more, more preferably 9% by weight or more, and further preferably 10% by weight or more. Therefore, the content of the monomer that can be copolymerized with the polyfunctional monomer in the monomer component A is a water resin composition that is comprehensively excellent in hot water whitening resistance, freeze-thaw resistance, and blocking resistance, and From the viewpoint of obtaining a water-based paint, it is 95% by weight or less, preferably 93% by weight or less, more preferably 91% by weight or less, and still more preferably 90% by weight or less.

  Further, the content of the polyfunctional monomer in the monomer component A is 50 from the viewpoint of obtaining a water-based resin composition and a water-based paint which are comprehensively excellent in hot water whitening resistance, freeze-thaw resistance and blocking resistance. % By weight or less. Therefore, the content of the monomer that can be copolymerized with the polyfunctional monomer in the monomer component A is a water resin composition that is comprehensively excellent in hot water whitening resistance, freeze-thaw resistance, and blocking resistance, and From the viewpoint of obtaining a water-based paint, it is 50% by weight or more.

  Examples of the monomer copolymerizable with the polyfunctional monomer include an aromatic monomer, an ethylenically unsaturated monomer, and the like. You may use the above together.

  Examples of aromatic monomers include styrene monomers and aralkyl (meth) acrylates, but the present invention is not limited to such examples.

  Examples of the styrenic monomer include styrene, α-methylstyrene, p-methylstyrene, tert-methylstyrene, chlorostyrene, vinyltoluene, and the like, but the present invention is limited only to such examples. is not. These monomers may be used alone or in combination of two or more. Styrene monomers have functional groups such as alkyl groups such as methyl and tert-butyl groups, nitro groups, nitrile groups, alkoxyl groups, acyl groups, sulfone groups, hydroxyl groups, and halogen atoms in the benzene ring. May be. Among the styrene monomers, styrene is preferable from the viewpoint of increasing the water resistance of the coating film.

  Examples of the aralkyl (meth) acrylate include aralkyl having 7 to 18 carbon atoms such as benzyl (meth) acrylate, phenylethyl (meth) acrylate, methylbenzyl (meth) acrylate, naphthylmethyl (meth) acrylate and the like. Although (meth) acrylate etc. are mentioned, this invention is not limited only to this illustration. These aralkyl (meth) acrylates may be used alone or in combination of two or more.

  Examples of the ethylenically unsaturated monomer include alkyl (meth) acrylate, hydroxyl group-containing (meth) acrylate, carboxyl group-containing monomer, oxo group-containing monomer, fluorine atom-containing monomer, and nitrogen atom-containing monomer. Examples include monomers, epoxy group-containing monomers, alkoxyalkyl (meth) acrylates, silane group-containing monomers, carbonyl group-containing monomers, aziridinyl group-containing monomers, and the present invention is only such examples. It is not limited to. These ethylenically unsaturated monomers may be used alone or in combination of two or more.

  Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, sec-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, tridecyl (meth) acrylate, cyclohexyl (meth) acrylate, n-lauryl (meth) Examples include acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and alkyl (meth) acrylate having 1 to 18 carbon atoms in the ester group such as isobornyl methacrylate. It is not limited only to hunt illustration. These monomers may be used alone or in combination of two or more.

  Examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxy Examples include hydroxyl group-containing (meth) acrylates having 1 to 18 carbon atoms in the ester group such as butyl (meth) acrylate, but the present invention is not limited to such examples. These hydroxyl group-containing (meth) acrylates may be used alone or in combination of two or more.

  Examples of the carboxyl group-containing monomer include (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid, maleic anhydride, maleic acid monomethyl ester, maleic acid monobutyl ester, and itaconic acid monomethyl. Examples thereof include carboxyl group-containing aliphatic monomers such as esters, itaconic acid monobutyl ester, and vinyl benzoic acid, but the present invention is not limited to such examples. These carboxyl group-containing monomers may be used alone or in combination of two or more. Among these carboxyl group-containing monomers, acrylic acid, methacrylic acid and itaconic acid are preferable, and acrylic acid and methacrylic acid are more preferable from the viewpoint of improving the dispersion stability of the emulsion particles.

  Examples of the oxo group-containing monomer include (di) ethylene glycol (methoxy) (meta) such as ethylene glycol (meth) acrylate, ethylene glycol methoxy (meth) acrylate, diethylene glycol (meth) acrylate, and diethylene glycol methoxy (meth) acrylate. ) Acrylate and the like, but the present invention is not limited to such examples. These oxo group-containing monomers may be used alone or in combination of two or more.

  Examples of the fluorine atom-containing monomer include fluorine atom-containing alkyl having 2 to 6 carbon atoms in an ester group such as trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, and octafluoropentyl (meth) acrylate. Although (meth) acrylate etc. are mentioned, this invention is not limited only to this illustration. These fluorine atom-containing monomers may be used alone or in combination of two or more.

  Examples of the nitrogen atom-containing monomer include (meth) acrylamide, N-monomethyl (meth) acrylamide, N-monoethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, and Nn-propyl (meth). Acrylamide, N-isopropyl (meth) acrylamide, methylenebis (meth) acrylamide, N-methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide, dimethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropylacrylamide, Acrylamide compounds such as diacetone acrylamide, nitrogen atom-containing (meth) acrylate compounds such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, N-vinylpyrrolidone, ( Data) but and acrylonitrile, the present invention is not limited only to those exemplified. These nitrogen atom-containing monomers may be used alone or in combination of two or more.

  Examples of the epoxy group-containing monomer include epoxy group-containing (meth) acrylates such as glycidyl (meth) acrylate, α-methylglycidyl (meth) acrylate, and glycidyl allyl ether. It is not limited to only. These epoxy group-containing monomers may be used alone or in combination of two or more.

  Examples of the alkoxyalkyl (meth) acrylate include methoxyethyl (meth) acrylate, methoxybutyl (meth) acrylate, ethoxybutyl (meth) acrylate, and trimethylolpropane tripropoxy (meth) acrylate. However, the present invention is not limited to such examples. These alkoxyalkyl (meth) acrylates may be used alone or in combination of two or more.

  Examples of the silane group-containing monomer include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (methoxyethoxy) silane, γ- (meth) acryloyloxypropyltrimethoxysilane, 2-styrylethyltrimethoxysilane, vinyltri Examples include chlorosilane, γ- (meth) acryloyloxypropylhydroxysilane, and γ- (meth) acryloyloxypropylmethylhydroxysilane, but the present invention is not limited to such examples. These silane group-containing monomers may be used alone or in combination of two or more.

  Examples of the carbonyl group-containing monomer include acrolein, humylstyrene, vinyl ethyl ketone, (meth) acryloxyalkylpropenal, acetonyl (meth) acrylate, diacetone (meth) acrylate, and 2-hydroxypropyl (meth) acrylate. Examples include acetyl acetate, butanediol-1,4-acrylate acetyl acetate, and 2- (acetoacetoxy) ethyl (meth) acrylate, but the present invention is not limited to such examples. These carbonyl group-containing monomers may be used alone or in combination of two or more.

  Examples of aziridinyl group-containing monomers include (meth) acryloylaziridine and 2-aziridinylethyl (meth) acrylate, but the present invention is not limited to such examples. These aziridinyl group-containing monomers may be used alone or in combination of two or more.

  Suitable monomers copolymerizable with the polyfunctional monomer include, for example, aromatic monomers, alkyl (meth) acrylates, hydroxyl group-containing (meth) acrylates, carboxyl group-containing monomers, and oxo group-containing monomers. Examples include monomers, fluorine atom-containing monomers, nitrogen atom-containing monomers, and epoxy group-containing monomers, and other ethylenically unsaturated monomers. Two or more types may be used in combination. Among the monomers copolymerizable with polyfunctional monomers, ethylenic acid is used from the viewpoint of obtaining water-based resin compositions and water-based paints that are comprehensively excellent in hot water whitening resistance, freeze-thaw resistance, and blocking resistance. Unsaturated monomers are preferred, alkyl (meth) acrylates are more preferred, and methyl methacrylate, tert-butyl (meth) acrylate and isobornyl methacrylate are more preferred.

  Further, in the present invention, from the viewpoint of imparting ultraviolet stability and ultraviolet absorption to the emulsion particles, an ultraviolet stable monomer, an ultraviolet absorbing monomer, and the like are simply used within a range that does not impede the purpose of the present invention. You may make it contain in a mass component.

  Examples of UV-stable monomers include 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine. 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloyl-1-methoxy-2,2,6,6-tetramethylpiperidine, 4-cyano- 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-croto Noylamino-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloylamino-1,2,2,6,6-pentamethylpiperidine, 4-sia -4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4-cyano- Examples include 4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine and the like. However, the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  Examples of the UV-absorbing monomer include benzotriazole-based UV-absorbing monomers and benzophenone-based UV-absorbing monomers, but the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more.

  Examples of the benzotriazole-based UV-absorbing monomer include 2- [2′-hydroxy-5 ′-(meth) acryloyloxymethylphenyl] -2H-benzotriazole and 2- [2′-hydroxy-5′-. (Meth) acryloyloxyethylphenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(meth) acryloyloxymethylphenyl] -5-tert-butyl-2H-benzotriazole, 2- [2 ′ -Hydroxy-5 '-(meth) acryloylaminomethyl-5'-tert-octylphenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-(meth) acryloyloxypropylphenyl] -2H-benzo Triazole, 2- [2′-hydroxy-5 ′-(meth) acryloyloxyhex Ruphenyl] -2H-benzotriazole, 2- [2′-hydroxy-3′-tert-butyl-5 ′-(meth) acryloyloxyethylphenyl] -2H-benzotriazole, 2- [2′-hydroxy-3 ′ -Tert-butyl-5 '-(meth) acryloyloxyethylphenyl] -5-chloro-2H-benzotriazole, 2- [2'-hydroxy-5'-tert-butyl-3'-(meth) acryloyloxyethyl Phenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(meth) acryloyloxyethylphenyl] -5-chloro-2H-benzotriazole, 2- [2′-hydroxy-5 ′-(meta ) Acrylyloxyethylphenyl] -5-cyano-2H-benzotriazole, 2- [2'-hydride Xyl-5 ′-(meth) acryloyloxyethylphenyl] -5-tert-butyl-2H-benzotriazole, 2- [2′-hydroxy-5 ′-(β- (meth) acryloyloxyethoxy) -3′- tert-butylphenyl] -4-tert-butyl-2H-benzotriazole, and the like, but the present invention is not limited to such examples. These benzotriazole-based UV-absorbing monomers may be used alone or in combination of two or more.

  Examples of the benzophenone-based UV-absorbing monomer include 2-hydroxy-4- (meth) acryloyloxybenzophenone, 2-hydroxy-4- [2-hydroxy-3- (meth) acryloyloxy] propoxybenzophenone, 2- Hydroxy-4- [2- (meth) acryloyloxy] ethoxybenzophenone, 2-hydroxy-4- [3- (meth) acryloyloxy-2-hydroxypropoxy] benzophenone, 2-hydroxy-3-tert-butyl-4- Examples include [2- (meth) acryloyloxy] butoxybenzophenone, but the present invention is not limited to such examples. These benzophenone-based ultraviolet absorbing monomers may be used alone or in combination of two or more.

  Examples of the method for emulsion polymerization of monomer component A include, for example, an aqueous medium containing a water-soluble organic solvent such as lower alcohol such as methanol and water, an emulsifier dissolved in a medium such as water, and a single amount under stirring. The method of dropping the body component A and the polymerization initiator, the method of dropping the monomer component A previously emulsified using an emulsifier and water, into water or an aqueous medium, and the like are mentioned. It is not limited only to the method. Note that the amount of the medium may be appropriately set in consideration of the nonvolatile content contained in the obtained aqueous resin composition. The medium may be charged in the reaction vessel in advance or used as a pre-emulsion. The medium may be used when a resin emulsion is produced by emulsion polymerization of monomer components as required.

  When the monomer component A is emulsion polymerized, the monomer component A, the emulsifier and the medium may be mixed and then the emulsion polymerization may be performed. The monomer component A, the emulsifier and the medium may be emulsified by stirring. The emulsion polymerization may be performed after preparing the pre-emulsion, or the emulsion polymerization may be performed by mixing at least one of the monomer component A, the emulsifier and the medium and the remaining pre-emulsion. The monomer component A, the emulsifier and the medium may be added all at once, may be added in portions, or may be continuously dropped.

  When the outer layer is formed on the emulsion particles contained in the resin emulsion obtained above, the monomer component is emulsion-polymerized in the resin emulsion in the same manner as described above to form the outer layer on the emulsion particles. An outer layer can be formed. Moreover, when forming an outer layer further on the emulsion particle | grains in which the said outer layer was formed, an outer layer is further formed on the said emulsion particle | grain by carrying out the emulsion polymerization of the monomer component in a resin emulsion like the above. Can be made. Thus, a resin emulsion containing emulsion particles having a multilayer structure can be prepared by a multistage emulsion polymerization method.

  When preparing emulsion particles having a multilayer structure, one or more stages of emulsion polymerization may be performed before the emulsion polymerization for forming the inner layer. The emulsion polymerization for forming the inner layer and the intermediate layer may be performed. One-stage or multi-stage emulsion polymerization may be performed between the emulsion polymerization to be formed. Moreover, you may perform one step or multiple steps | paragraphs of emulsion polymerization between the emulsion polymerization which forms the said intermediate | middle layer, and the emulsion polymerization which forms the said outer layer. Furthermore, after the emulsion polymerization for forming the outer layer, one or more stages of emulsion polymerization may be performed.

  Examples of the emulsifier include an anionic emulsifier, a nonionic emulsifier, a cationic emulsifier, an amphoteric emulsifier, and a polymer emulsifier. These emulsifiers may be used alone or in combination of two or more.

  Examples of the anionic emulsifier include alkyl sulfate salts such as ammonium dodecyl sulfate and sodium dodecyl sulfate; alkyl sulfonate salts such as ammonium dodecyl sulfonate, sodium dodecyl sulfonate and sodium alkyl diphenyl ether disulfonate; ammonium dodecyl benzene sulfonate and sodium dodecyl naphthalene sulfonate. Polyoxyethylene alkyl sulfonate salts; polyoxyethylene alkyl sulfate salts; polyoxyethylene alkyl aryl sulfate salts; dialkyl sulfosuccinates; aryl sulfonic acid-formalin condensates; ammonium laurate, sodium stearate, etc. Fatty acid salt; bis ( (Rioxyethylene polycyclic phenyl ether) methacrylate sulfonate salt, propenyl-alkylsulfosuccinate ester salt, (meth) acrylic acid polyoxyethylene sulfonate salt, (meth) acrylic acid polyoxyethylene phosphonate salt, allyloxymethylalkyloxypoly Sulfuric acid ester having an allyl group, such as sulfonate salt of oxyethylene or a salt thereof; Sulfuric acid ester salt of allyloxymethylalkoxyethyl polyoxyethylene, polyoxyalkylene alkenyl ether ammonium sulfate, and the like. It is not limited to.

  Nonionic emulsifiers include, for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, condensate of polyethylene glycol and polypropylene glycol, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid monoglyceride, ethylene oxide and aliphatic Examples include condensation products with amines, allyloxymethylalkoxyethylhydroxypolyoxyethylene, and polyoxyalkylene alkenyl ethers, but the present invention is not limited to such examples.

  Examples of the cationic emulsifier include alkylammonium salts such as dodecylammonium chloride, but the present invention is not limited to such examples.

  Examples of amphoteric emulsifiers include betaine ester type emulsifiers, but the present invention is not limited to such examples.

  Examples of the polymer emulsifier include poly (meth) acrylates such as sodium polyacrylate; polyvinyl alcohol; polyvinyl pyrrolidone; polyhydroxyalkyl (meth) acrylates such as polyhydroxyethyl acrylate; single polymers constituting these polymers. Although the copolymer etc. which use 1 or more types of a monomer as a copolymerization component are mentioned, this invention is not limited only to this illustration.

  Further, as the emulsifier, an emulsifier having a polymerizable group, that is, a so-called reactive emulsifier, from the viewpoint of obtaining an aqueous resin composition and an aqueous paint that are comprehensively excellent in hot water whitening resistance, freeze-thaw resistance, and blocking resistance. From the viewpoint of environmental protection, non-nonylphenyl emulsifiers are preferred.

  As the reactive emulsifier, for example, propenyl-alkylsulfosuccinic acid ester salt, (meth) acrylic acid polyoxyethylene sulfonate salt, (meth) acrylic acid polyoxyethylene phosphonate salt [for example, manufactured by Sanyo Chemical Industries, Ltd., Product name: Eleminol RS-30, etc.], polyoxyethylene alkylpropenyl phenyl ether sulfonate salt [for example, product name: Aqualon HS-10, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.], allyloxymethylalkyloxypolyoxyethylene Sulfonate salt [for example, product name: Aqualon KH-10 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.], sulfonate salt of allyloxymethylnonylphenoxyethylhydroxypolyoxyethylene [for example, product name: ADEKA manufactured by ADEKA Corporation Rear soap SE-10 etc.), Ryloxymethylalkoxyethylhydroxypolyoxyethylene sulfate ester salt (for example, manufactured by ADEKA, trade name: Adekaria soap SR-10, SR-30, etc.), bis (polyoxyethylene polycyclic phenyl ether) methacrylated sulfonate Salts (for example, Nippon Emulsifier Co., Ltd., trade name: Antox MS-60, etc.), allyloxymethylalkoxyethylhydroxypolyoxyethylene [eg, ADEKA Corporation, trade name: Adeka Soap ER-20, etc. ], Polyoxyethylene alkylpropenyl phenyl ether [for example, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon RN-20, etc.], allyloxymethylnonylphenoxyethyl hydroxypolyoxyethylene [for example, manufactured by ADEKA Corporation, Product Name: Adekaria Soap E-10, etc.) and the like, the present invention is not limited only to those exemplified.

  The amount of the emulsifier is preferably 0.5 parts by weight or more, more preferably 1 part by weight or more, further preferably 2 parts by weight or more, particularly preferably from the viewpoint of improving the polymerization stability per 100 parts by weight of the monomer component A. Is 3 parts by weight or more, and preferably 10 parts by weight or less, more preferably 6 parts by weight, from the viewpoint of obtaining a water-based resin composition and a water-based paint which are comprehensively excellent in hot water whitening resistance, freeze-thaw resistance and blocking resistance. The amount is not more than parts by weight, more preferably not more than 5 parts by weight, particularly preferably not more than 4 parts by weight.

  Examples of the polymerization initiator include azobisisobutyronitrile, 2,2-azobis (2-methylbutyronitrile), 2,2-azobis (2,4-dimethylvaleronitrile), 2,2-azobis ( Azo compounds such as 2-diaminopropane) hydrochloride, 4,4-azobis (4-cyanovaleric acid), 2,2-azobis (2-methylpropionamidine); persulfates such as ammonium persulfate and potassium persulfate; Examples of the peroxide include peroxides such as hydrogen peroxide, benzoyl peroxide, parachlorobenzoyl peroxide, lauroyl peroxide, and ammonium peroxide. However, the present invention is not limited to such examples. These polymerization initiators may be used alone or in combination of two or more.

  The amount of the polymerization initiator is preferably 0.05 parts by weight or more, more preferably from the viewpoint of increasing the polymerization rate and reducing the residual amount of the unreacted monomer component A per 100 parts by weight of the monomer component A. From the viewpoint of obtaining a water-based resin composition and a water-based paint which are 0.1 parts by weight or more and are comprehensively excellent in hot water whitening resistance, freeze-thaw resistance and blocking resistance, preferably 1 part by weight or less, more preferably 0.5 parts by weight or less.

  The method for adding the polymerization initiator is not particularly limited. Examples of the addition method include batch charging, divided charging, and continuous dripping. Further, from the viewpoint of accelerating the completion time of the polymerization reaction, a part of the polymerization initiator may be added before or after the monomer component A is added to the reaction system.

  In order to accelerate the decomposition of the polymerization initiator, for example, a reducing agent such as sodium bisulfite and a polymerization initiator decomposition agent such as transition metal salt such as ferrous sulfate are added in an appropriate amount to the reaction system. Also good.

  A chain transfer agent can be used to adjust the weight average molecular weight of the emulsion particles. Examples of the chain transfer agent include 2-ethylhexyl thioglycolate, tert-dodecyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, mercaptoacetic acid, mercaptopropionic acid, 2-mercaptoethanol, α-methylstyrene, α-methyl. Although a styrene dimer etc. are mentioned, this invention is not limited only to this illustration. These chain transfer agents may be used alone or in combination of two or more. The amount of the chain transfer agent is preferably 0.01 to 10 parts by weight per 100 parts by weight of the monomer component A from the viewpoint of adjusting the weight average molecular weight of the emulsion particles.

  Moreover, you may add additives, such as a pH buffer, a chelating agent, and a film-forming aid, in the reaction system as needed. Since the amount of the additive varies depending on the type, it cannot be determined unconditionally, but is usually preferably about 0.01 to 5 parts by weight, more preferably about 0.1 to 5 parts by weight per 100 parts by weight of the monomer component A. About 3 parts by weight.

  Although the atmosphere at the time of carrying out emulsion polymerization of the monomer component A is not specifically limited, It is preferable that it is inert gas, such as nitrogen gas, from a viewpoint of improving the efficiency of a polymerization initiator.

  Although the polymerization temperature at the time of carrying out emulsion polymerization of the monomer component A does not have limitation, Usually, Preferably it is 50-100 degreeC, More preferably, it is 60-95 degreeC. The polymerization temperature may be constant or may be changed during the polymerization reaction.

  The polymerization time for emulsion polymerization of the monomer component A is not particularly limited and may be appropriately set according to the progress of the polymerization reaction, but is usually about 2 to 9 hours.

  In addition, when the monomer component A is emulsion-polymerized, part or all of the acidic groups of the obtained polymer may be neutralized with a neutralizing agent. The neutralizing agent may be used after the monomer component is added in the final stage. For example, the neutralizing agent may be used between the first stage polymerization reaction and the second stage polymerization reaction. It may be used at the end of the polymerization reaction.

  Examples of the neutralizing agent include alkali metal and alkaline earth metal hydroxides such as sodium hydroxide; alkali metal and alkaline earth metal carbonates such as calcium carbonate; and organic amines such as ammonia and monomethylamine. Although an alkaline substance is mentioned, this invention is not limited only to this illustration. Among these neutralizing agents, an alkaline substance having volatility such as ammonia is preferable from the viewpoint of improving warm water whitening resistance. The neutralizing agent can be used as an aqueous solution, for example.

  In addition, when the monomer component is emulsion-polymerized, a silane coupling agent may be used in an appropriate amount from the viewpoint of improving warm water whitening resistance. Examples of the silane coupling agent include a silane coupling agent having a polymerizable unsaturated bond such as a (meth) acryloyl group, a vinyl group, an allyl group, and a propenyl group. It is not limited.

  By polymerizing the monomer component A as described above, the polymer (I) forming the inner layer is obtained in the form of emulsion particles.

  Since the polymer (I) uses a polyfunctional monomer for the monomer component A, it has a crosslinked structure. The weight average molecular weight of the polymer (I) is preferably 100,000 or more, more preferably from the viewpoint of obtaining a water-based resin composition and a water-based paint which are comprehensively excellent in hot water whitening resistance, freeze-thaw resistance and blocking resistance. Is 300,000 or more, more preferably 550,000 or more, and particularly preferably 600,000 or more. The upper limit of the weight average molecular weight of the polymer (I) is not particularly limited because the polymer (I) has a cross-linked structure, making it difficult to measure the weight average molecular weight. From the viewpoint of improving the freeze-thaw property, it is preferably 5 million or less.

  In addition, in this specification, the weight average molecular weight uses gel permeation chromatography [manufactured by Tosoh Corporation, product number: HLC-8120GPC, column: TSKgel G-5000HXL and TSKgel GMHXL-L used in series]. The weight average molecular weight (in terms of polystyrene) measured by

  Next, after forming an inner layer made of polymer (I), an outer layer made of polymer (II) having a glass transition temperature of 40 ° C. or lower is formed on the surface of the inner layer. In the present invention, since the glass transition temperature of the polymer (II) is 40 ° C. or lower, an aqueous resin composition and an aqueous paint excellent in hot water whitening resistance, freeze-thaw resistance and blocking resistance are obtained. be able to.

  When the monomer component B is subjected to emulsion polymerization, the emulsion component may be subjected to emulsion polymerization after the polymerization reaction rate of the polymer (I) reaches 90% or more, preferably 95% or more. It is preferable from the viewpoint of forming a layer separation structure.

  In addition, after forming the inner layer made of the polymer (I) and before forming the outer layer made of the polymer (II), it is made of another polymer, if necessary, as long as the object of the present invention is not hindered. A layer may be formed. Therefore, in the method for producing the aqueous resin composition of the present invention, the object of the present invention is not hindered after forming the inner layer made of the polymer (I) and before forming the outer layer made of the polymer (II). Within the range, if necessary, an operation of forming a layer made of another polymer may be included.

  The monomer component B only needs to have a composition in which the glass transition temperature of the polymer (II) is 40 ° C. or lower, and the composition is not particularly limited.

  As monomers used for the monomer component B, aromatic monomers, alkyl (meth) acrylates, hydroxyl group-containing (meth) acrylates, carboxyl group-containing monomers used for the monomer component A, Oxo group-containing monomer, fluorine atom-containing monomer, nitrogen atom-containing monomer, epoxy group-containing monomer, alkoxyalkyl (meth) acrylate, silane group-containing monomer, carbonyl group-containing monomer, aziridinyl Although a group containing monomer etc. are mentioned, this invention is not limited only to this illustration. The monomers copolymerizable with these carboxyl group-containing monomers may be used alone or in combination of two or more.

  The monomer component B preferably contains a carboxyl group-containing monomer from the viewpoint of improving freeze-thaw resistance. As a carboxyl group-containing monomer, the same thing as the carboxyl group-containing monomer used for the monomer component A can be illustrated. The carboxyl group-containing monomers may be used alone or in combination of two or more. Among the carboxyl group-containing monomers, acrylic acid, methacrylic acid and itaconic acid are preferable, and acrylic acid and methacrylic acid are more preferable from the viewpoint of improving the dispersion stability of the emulsion particles.

  The content of the carboxyl group-containing monomer in the monomer component B is preferably 1% by weight or more, more preferably 2% by weight or more from the viewpoint of improving the freeze-thaw resistance, and the hot water whitening resistance is improved. From the viewpoint of making it, it is preferably 10% by weight or less, more preferably 5% by weight or less.

  Among the monomers copolymerizable with the carboxyl group-containing monomer, from the viewpoint of obtaining a water-based resin composition and a water-based paint that are comprehensively excellent in hot water whitening resistance, freeze-thaw resistance, and blocking resistance, alkyl (Meth) acrylate is preferred, and tert-butyl (meth) acrylate, cyclohexyl (meth) acrylate and 2-ethylhexyl (meth) acrylate are more preferred.

  The content of the monomer copolymerizable with the carboxyl group-containing monomer in the monomer component B is an aqueous resin composition and aqueous solution that are comprehensively excellent in hot water whitening resistance, freeze-thaw resistance, and blocking resistance. From the viewpoint of obtaining a paint, it is preferably 90% by weight or more, more preferably 95% by weight or more, and from the viewpoint of improving freeze-thaw resistance, it is preferably 99% by weight or less, more preferably 98% by weight or less.

  The method for polymerizing the monomer component B and the polymerization conditions may be the same as the method for polymerizing the monomer A and the polymerization conditions.

  By emulsion polymerization of the monomer component B as described above, emulsion particles in which the polymer (II) forming the outer layer is formed on the surface of the inner layer can be obtained. In addition, on the surface of the outer layer made of the polymer (II), a surface layer made of another polymer may be further formed as necessary within the range not hindering the object of the present invention.

  The polymer (II) may have a crosslinked structure. The weight average molecular weight of the polymer (II) is that when the polymer (II) has a crosslinked structure and when the polymer (II) does not have a crosslinked structure, warm water whitening resistance, freeze-thaw resistance and blocking resistance From the viewpoint of obtaining a water-based resin composition and a water-based paint that are comprehensively excellent in properties, it is preferably 10,000 or more, more preferably 100,000 or more, still more preferably 300,000 or more, and particularly preferably 500,000 or more. The upper limit of the weight average molecular weight of the polymer (II) is not particularly limited because it is difficult to measure the weight average molecular weight when it has a crosslinked structure, but when it does not have a crosslinked structure, it is freeze-thaw resistant. From the viewpoint of improving heat resistance and hot water whitening resistance, it is preferably 5 million or less.

  The glass transition temperature of the polymer (I) is preferably 70 ° C. or higher, more preferably 80 ° C. or higher, more preferably 90 ° C. or higher, from the viewpoint of improving hot water whitening resistance, freeze-thaw resistance and blocking resistance. From the viewpoint of improving freeze-thaw resistance, the temperature is preferably 200 ° C. or lower. The glass transition temperature of the polymer (I) can be easily adjusted by adjusting the composition of the monomer used for the monomer component A.

  The content of the monomer having a glass transition temperature of 80 ° C. or higher in the monomer component used in the polymer (I) is 80% from the viewpoint of improving hot water whitening resistance, freeze-thaw resistance, and blocking resistance. % Or more, preferably 85% or more, more preferably 90% or more. In the present specification, “a monomer having a glass transition temperature of 80 ° C. or higher” means a monomer having a glass transition temperature of a homopolymer composed of the monomer of 80 ° C. or higher. Examples of the monomer having a glass transition temperature of 80 ° C. or higher include acrylic acid, methacrylic acid, methyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, 4-methacryloyloxy-2, Examples include 2,6,6-tetramethylpiperidine, but the present invention is not limited to such examples.

  The glass transition temperature of the polymer (II) is 40 ° C. or lower, preferably 35 ° C. or lower, more preferably 30 ° C. or lower, from the viewpoint of improving the freeze-thaw resistance. The glass transition temperature of the polymer (II) is preferably −40 ° C. or higher, more preferably −25 ° C. or higher, and further preferably −10 ° C. or higher, from the viewpoint of improving blocking resistance. The glass transition temperature of the polymer (II) can be easily adjusted by adjusting the composition of the monomer used for the monomer component B.

  The glass transition temperature of the emulsion particles is preferably −10 ° C. or higher, more preferably 0 ° C. or higher, more preferably 10 ° C. or higher, from the viewpoint of improving hot water whitening resistance, and from the viewpoint of improving freeze-thaw resistance. The temperature is preferably 60 ° C. or lower, more preferably 55 ° C. or lower, and still more preferably 50 ° C. or lower.

In the present specification, the glass transition temperature of the polymer is expressed by the following formula: the glass transition temperature of the homopolymer of the monomer used in the monomer component constituting the polymer.
1 / Tg = Σ (Wm / Tgm) / 100
[Wm represents the content (% by weight) of monomer m in the monomer component constituting the polymer, and Tgm represents the glass transition temperature (absolute temperature: K) of the homopolymer of monomer m. ]
The temperature calculated | required based on the Formula of Fox (Fox) represented by these.

  The glass transition temperature of the polymer is, for example, 83 ° C. for a cyclohexyl methacrylate homopolymer, -70 ° C. for a homopolymer of 2-ethylhexyl acrylate, 130 ° C. for a homopolymer of methacrylic acid, and a single weight of isobornyl methacrylate. 180 ° C for coalescence, 100 ° C for homopolymer of styrene, 105 ° C for homopolymer of methyl methacrylate, 95 ° C for homopolymer of acrylic acid, for homopolymer of γ-methacryloxypropyltrimethoxysilane (TMSMA) 70 ° C., -56 ° C. for butyl acrylate homopolymer, and 130 ° C. for 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine homopolymer.

  The glass transition temperature of the polymer is a value obtained based on the Fox equation, but the measured value of the glass transition temperature of the polymer was obtained based on the Fox equation. The value is preferably the same. The actual measured value of the glass transition temperature of the polymer can be obtained, for example, by measuring the differential scanning calorific value.

  Examples of the differential scanning calorimeter measuring device include Seiko Instruments Inc., product number: DSC220C. Further, when measuring the differential scanning calorific value, a method of drawing a differential scanning calorific value (DSC) curve, a method of obtaining a first derivative curve from the differential scanning calorific value (DSC) curve, a method of performing a smoothing process, and a method of obtaining a target peak temperature There is no limitation in particular. For example, when the measuring device is used, the drawing may be performed from data obtained by using the measuring device. At that time, analysis software capable of performing mathematical processing can be used. Examples of the analysis software include analysis software [manufactured by Seiko Instruments Inc., product number: EXSTAR6000], but the present invention is not limited to such examples. In addition, the peak temperature obtained in this way may include an error due to plotting of about 5 ° C. up and down.

  The solubility parameter of the polymer (II) (hereinafter also referred to as SP value) is preferably higher than the SP value of the polymer (I) from the viewpoint of forming a layer separation structure in the emulsion particles. Further, the difference between the SP value of the polymer (I) and the SP value of the polymer (II) is preferably large from the viewpoint of forming a layer separation structure in the emulsion particles. In the present invention, the emulsion particles include a polymer (I) in which a polyfunctional monomer having a low SP value is used in a large amount and a polymer (II) in which a carboxyl group-containing monomer having a high SP value is used. ), It has an ideal structure in which the inner layer and the outer layer are clearly separated.

  The SP value is a value defined by the regular solution theory introduced by Hildebrand, and is also a measure of the solubility of the binary solution. In general, substances having similar SP values tend to be mixed with each other. Therefore, the SP value is also a measure for judging the ease of mixing of the solute and the solvent.

  The weight ratio of the polymer (I) to the polymer (II) [polymer (I) / polymer (II)] is 25/75 or more, preferably 35/65 or more from the viewpoint of improving blocking resistance. From the viewpoint of improving hot water whitening resistance and freeze-thaw resistance, it is 75/25 or less, preferably 65/35 or less.

  The total content of the polymer (I) and the polymer (II) in the emulsion particles is 50% by weight or more, preferably 65% by weight or more, from the viewpoint of improving freeze-thaw resistance and hot water whitening resistance. The higher the total content of the polymer (I) and the polymer (II) in the emulsion particles, the better. The upper limit is 100% by weight.

  The content of the carboxyl group-containing monomer in the monomer component used in the polymer (II) is the carboxyl content in the monomer component used in the polymer (I) from the viewpoint of forming a layer separation structure in the emulsion particles. It is preferably higher than the content of the group-containing monomer. The difference between the content of the carboxyl group-containing monomer in the monomer component used in the polymer (II) and the content of the carboxyl group-containing monomer in the monomer component used in the polymer (I) is From the viewpoint of obtaining emulsion particles having an ideal structure in which the inner layer and the outer layer are clearly separated, it is preferably 1 point or more, more preferably 3 points or more.

  After preparing the inner layer made of the polymer (I) as described above, an outer layer made of the polymer (II) is formed on the inner layer to obtain a resin emulsion containing emulsion particles having the inner layer and the outer layer. . The aqueous resin composition of the present invention contains a resin emulsion containing emulsion particles thus obtained.

  The minimum film-forming temperature of the aqueous resin composition of the present invention is preferably 60 ° C. or lower, more preferably 50 ° C. or lower, and further preferably 40 ° C. or lower, from the viewpoint of improving freeze-thaw resistance. Further, the lower limit value of the minimum film-forming temperature of the aqueous resin composition of the present invention is preferably −5 ° C. or higher, more preferably 5 ° C. or higher, and further preferably 20 ° C. or higher, from the viewpoint of improving freeze-thaw resistance. is there.

  In this specification, the minimum film-forming temperature of the aqueous resin composition is applied with an applicator so that the thickness of the aqueous resin composition is 0.2 mm on a glass plate placed on a thermal gradient tester. It means the temperature when it is dried and cracks occur.

  The nonvolatile content in the aqueous resin composition of the present invention is preferably 30% by weight or more, more preferably 40% by weight or more from the viewpoint of improving productivity, and preferably 70% by weight from the viewpoint of improving handleability. Below, more preferably 60% by weight or less.

In the present specification, the non-volatile content in the aqueous resin composition is determined by weighing 1 g of the aqueous resin composition and drying it with a hot air dryer at a temperature of 110 ° C. for 1 hour.
[Nonvolatile content in water-based resin composition (mass%)]
= ([Residue mass] ÷ [aqueous resin composition 1 g]) × 100
Means the value obtained based on

  From the viewpoint of improving the storage stability of the emulsion particles, the average particle diameter of the emulsion particles is preferably 30 nm or more, more preferably 50 nm or more, and even more preferably 70 nm or more, preferably from the viewpoint of improving freeze-thaw resistance. Is 250 nm or less, more preferably 200 nm or less.

  In the present specification, the average particle size of the emulsion particles is measured using a particle size distribution measuring instrument (manufactured by Particle Sizing Systems, trade name: NICOMP Model 380) by a dynamic light scattering method. It means the volume average particle diameter.

  The aqueous resin composition of the present invention can be imparted with crosslinkability by further containing a crosslinking agent. As a crosslinking agent, a crosslinking reaction may be started at room temperature, or a crosslinking reaction may be initiated by heat. By containing a crosslinking agent in the aqueous resin composition of the present invention, it is possible to improve warm water whitening resistance and blocking resistance.

  Suitable cross-linking agents include, for example, oxazoline group-containing compounds, isocyanate group-containing compounds, aminoplast resins, and the like. These crosslinking agents may be used alone or in combination of two or more. Among these crosslinking agents, an oxazoline group-containing compound is preferable from the viewpoint of improving hot water whitening resistance and blocking resistance.

  The oxazoline group-containing compound is a compound having in the molecule two or more oxazoline groups that can react with the carboxyl group that the carboxyl group-containing monomer used as the monomer component has as a functional group.

  Examples of the oxazoline group-containing compound include 2,2′-bis (2-oxazoline), 2,2′-methylene-bis (2-oxazoline), 2,2′-ethylene-bis (2-oxazoline), 2 , 2'-trimethylene-bis (2-oxazoline), 2,2'-tetramethylene-bis (2-oxazoline), 2,2'-hexamethylene-bis (2-oxazoline), 2,2'-octamethylene -Bis (2-oxazoline), 2,2'-ethylene-bis (4,4'-dimethyl-2-oxazoline), 2,2'-p-phenylene-bis (2-oxazoline), 2,2'- m-phenylene-bis (2-oxazoline), 2,2′-m-phenylene-bis (4,4′-dimethyl-2-oxazoline), bis (2-oxazolinylcyclohexane) sulfi , Bis (2-oxazolinyl sulfonyl norbornane) sulfide, but like oxazoline ring-containing polymer, the present invention is not limited only to those exemplified. These oxazoline group-containing compounds may be used alone or in combination of two or more. Among the oxazoline group-containing compounds, from the viewpoint of improving the reactivity, a water-soluble oxazoline group-containing compound is preferable, and a water-soluble oxazoline ring-containing polymer is more preferable.

  The oxazoline ring-containing polymer contains an addition-polymerizable oxazoline as an essential component, and can be easily prepared by polymerizing a monomer component containing a monomer copolymerizable with the addition-polymerizable oxazoline as necessary. Can do.

  Examples of the addition polymerizable oxazoline include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, Examples include 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline. It is not limited to only. These addition polymerizable oxazolines may be used alone or in combination of two or more. Among these addition-polymerizable oxazolines, 2-isopropenyl-2-oxazoline is preferable because it is easily available.

  Examples of monomers copolymerizable with the addition polymerizable oxazoline include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and tert-butyl (meth) acrylate. , Cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- Hydroxypropyl (meth) acrylate, monoesterified product of (meth) acrylic acid and polyethylene glycol, 2-aminoethyl (meth) acrylate and its salt, caprolactone modified product of (meth) acrylic acid, (meth) acrylic -(2,2,6,6-tetramethylpiperidine, (meth) acrylic acid-1, methacrylic acid esters such as 1,2,2,6,6-pentamethylpiperidine; sodium (meth) acrylate, (meta ) (Meth) acrylates such as potassium acrylate and ammonium (meth) acrylate; unsaturated nitriles such as (meth) acrylonitrile; (meth) acrylamide, N-methylol (meth) acrylamide, N- (2-hydroxyethyl) ) Unsaturated amides such as (meth) acrylamide; Vinyl esters such as vinyl acetate and vinyl propionate; Vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; Vinyl chloride, vinylidene chloride, vinyl fluoride, etc. Halogen-containing α, β-unsaturated fat Hydrocarbon compounds; styrene, alpha-methyl styrene, alpha such as sodium styrene sulfonate, beta-although such unsaturated aromatic hydrocarbon compounds, the present invention is not limited only to those exemplified. These monomers copolymerizable with the addition-polymerizable oxazoline may be used alone or in combination of two or more.

  Oxazoline group-containing compounds are easily commercially available as, for example, Nippon Shokubai Co., Ltd., trade names: Epocross WS-500, Epocross WS-700, Epocross K-2010, Epocross K-2020, Epocross K-2030, etc. can do. Among these, from the viewpoint of improving reactivity, water-soluble oxazoline group-containing compounds such as Nippon Shokubai Co., Ltd., trade names: Epocross WS-500 and Epocross WS-700 are preferable.

  The isocyanate group-containing compound is a compound containing an isocyanate group that can react with a hydroxyl group that the hydroxyl group-containing monomer used as the monomer component has as a functional group.

  Examples of the isocyanate group-containing compound include water-dispersed (block) polyisocyanate. In addition, (block) polyisocyanate means polyisocyanate and / or block polyisocyanate.

  Examples of the water-dispersed polyisocyanate include those obtained by dispersing a polyisocyanate imparted with hydrophilicity by a polyethylene oxide chain in water with an anionic dispersant or a nonionic dispersant.

  Examples of the polyisocyanate include diisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate; and polyisocyanate derivatives (modified products) of these diisocyanates such as trimethylolpropane adduct, burette, and isocyanurate. The present invention is not limited to such examples. These polyisocyanates may be used alone or in combination of two or more.

  Water-dispersed polyisocyanates are, for example, made by Nippon Polyurethane Industry Co., Ltd., trade names: Aquanate 100, Aquanate 110, Aquanate 200, Aquanate 210, etc .; manufactured by Sumika Bayer Urethane Co., Ltd., trade name: Baihijur TPLS-2032, SUB-isocyanate L801, etc .; manufactured by Mitsui Takeda Chemical Co., Ltd., trade names: Takenate WD-720, Takenate WD-725, Takenate WD-220, etc .; manufactured by Dainichi Seika Kogyo Co., Ltd., trade name: Rezamin It can be easily obtained commercially as D-56 or the like.

  The water-dispersed block polyisocyanate is obtained by blocking the isocyanate group of the water-dispersed polyisocyanate with a blocking agent. Examples of the blocking agent include diethyl malonate, ethyl acetoacetate, ε-caprolactam, butanone oxime, cyclohexanone oxime, 1,2,4-triazole, dimethyl-1,2,4-triazole, and 3,5-dimethylpyrazole. , Imidazole and the like can be mentioned, but the present invention is not limited to such examples. These blocking agents may be used alone or in combination of two or more. Among these blocking agents, those that cleave at a temperature of 160 ° C. or lower, preferably 150 ° C. or lower are desirable. Suitable blocking agents include, for example, butanone oxime, cyclohexanone oxime, 3,5-dimethylpyrazole and the like. Of these, butanone oxime is more preferred.

  Examples of the water-dispersed block polyisocyanate include Mitsui Takeda Chemical Co., Ltd., trade names: Takenate WB-720, Takenate WB-730, Takenate WB-920, etc .; Sumika Bayer Urethane Co., Ltd., trade name: Bihijur BL116, Bihijoule BL5140, Bihijoule BL5235, Bihijoule TPLS2186, Death Module VPLS2310, etc. can be easily obtained commercially.

  The functional group of polymer (II) contained in the emulsion particles (functional group for oxazoline group-containing compound: carboxyl group, functional group for isocyanate group-containing compound: hydroxyl group), oxazoline group-containing compound, isocyanate group-containing compound, etc. Equivalent ratio (functional group of polymer (II) / functional group of crosslinking agent) with the functional group of the crosslinking agent (functional group of oxazoline group-containing compound: oxazoline group, functional group of isocyanate group-containing compound: isocyanate group) is: Usually, it is preferably 0.1 to 2.5, more preferably 0.2 to 2, and still more preferably 0.3 to 1.8.

  The aminoplast resin is an addition condensate of a compound having an amino group such as melamine or guanamine with formaldehyde, and is also called an amino resin.

  Examples of aminoplast resins include dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, hexamethylol melamine, fully alkyl methylated melamine, fully alkyl butylated melamine, fully alkyl isobutylated melamine, completely Melamine resins such as alkyl mixed etherified melamine, methylol group methylated melamine, imino group methylated melamine, methylol group mixed etherified melamine, imino group mixed etherified melamine; butylated benzoguanamine, methyl / ethyl mixed alkyl Benzoguanamine, methyl / butyl mixed alkylated benzoguanamine, guanamine resins such as butylated glycoluril, and the like, but the present invention is limited only to such examples. Not to. These aminoplast resins may be used alone or in combination of two or more.

  Aminoplast resin is, for example, manufactured by Mitsui Cytec Co., Ltd., trade names: My Coat 506, My Coat 1128, Cymel 232, Cymel 235, Cymel 254, Cymel 303, Cymel 325, Cymel 370, Cymel 771, Cymel 1170, etc. It can be easily obtained commercially.

  The amount of aminoplast resin is usually such that the weight ratio of the solid content of the polymer contained in the emulsion particles to the solid content of the aminoplast resin (solid content of polymer / solid content of aminoplast resin) is 60/40. It is preferable to adjust so that it may be set to -99/1.

  In the present invention, in addition to the crosslinking agent described above, for example, a carbodiimide compound; a crosslinking agent such as a polyvalent metal compound represented by a zirconium compound, a zinc compound, a titanium compound, an aluminum compound, etc. It can be used as long as it is not inhibited.

  If necessary, the aqueous resin composition of the present invention can contain a pigment. Examples of the pigment include organic pigments and inorganic pigments, and these may be used alone or in combination of two or more.

  Examples of organic pigments include azo pigments such as benzidine and hansa yellow, azomethine pigments, methine pigments, anthraquinone pigments, phthalocyanine pigments such as phthalocyanine blue, perinone pigments, perylene pigments, diketopyrrolopyrrole pigments, thioindigo pigments, and iminoisoindoline. Pigments, iminoisoindolinone pigments, quinacridone pigments such as quinacridone red and quinacridone violet, flavantron pigments, indanthrone pigments, anthrapyrimidine pigments, carbazole pigments, monoarylide yellow, diaryride yellow, benzimidazolone yellow, tolyl orange , Naphthol orange, quinophthalone pigment, and the like, but the present invention is not limited to such examples. These organic pigments may be used alone or in combination of two or more.

  Examples of inorganic pigments include titanium dioxide, antimony trioxide, zinc white, lithopone, lead white, red iron oxide, black iron oxide, iron oxide, chromium oxide green, carbon black, yellow lead, molybdenum red, ferrocyanide Pigment with flat shape such as ferric (Prussian blue), ultramarine, lead chromate, mica, clay, aluminum powder, talc, aluminum silicate, calcium carbonate, magnesium hydroxide, aluminum hydroxide And extender pigments such as barium sulfate and magnesium carbonate, but the present invention is not limited to such examples. These inorganic pigments may be used alone or in combination of two or more.

  The amount of the pigment per 100 parts by weight of the non-volatile content of the resin emulsion is preferably 50 parts by weight or more, more preferably 60 parts by weight or more from the viewpoint of improving blocking resistance, and resistance to warm water whitening and freeze-thaw resistance. From the viewpoint of improving the ratio, it is preferably 190 parts by weight or less.

  The aqueous resin composition of the present invention may contain other resin emulsions other than the resin emulsion as long as the object of the present invention is not impaired. In that case, it is included in the aqueous resin composition. What is necessary is just to adjust so that the average particle diameter of the whole emulsion particle | grains currently may become in the said range.

  In addition, the aqueous resin composition of the present invention includes, for example, an ultraviolet absorber, an ultraviolet stabilizer, a filler, a leveling agent, a dispersant, a thickener, a wetting agent, a plasticizer, and the like within the range in which the object of the present invention is not inhibited. Additives such as additives, stabilizers, dyes, and antioxidants may be contained in appropriate amounts.

  The aqueous resin composition of the present invention may be applied alone as a single layer, or may be applied by recoating two or more layers. When the coating is performed by recoating two or more layers, only some of the layers may be formed by the aqueous resin composition of the present invention, and all the layers may be formed by the aqueous resin composition of the present invention. Also good. For overcoating, for example, a first layer (for example, undercoat layer) coating is applied to an object that has been subjected to primer treatment or sealer treatment, and then dried, and then for the second layer (for example, topcoat layer). Although the method of overcoating and drying a paint is mentioned, this invention is not limited by this method. Examples of the method for applying the aqueous resin composition of the present invention include a coating method using a brush, a bar coater, an applicator, an air spray, an airless spray, a roll coater, a flow coater, etc. It is not limited to illustration only.

  The aqueous resin composition of the present invention is excellent in blocking resistance because the inner layer is formed of the polymer (I) obtained by emulsion polymerization of a monomer component containing a polyfunctional monomer. . In addition, since the aqueous resin composition of the present invention contains emulsion particles having the above-described configuration, it is excellent in film-forming properties, and thus is excellent in freeze-thaw resistance even when a large amount of pigment is contained. ing. As described above, the aqueous resin composition of the present invention is comprehensively excellent in hot water whitening resistance, freeze-thaw resistance, and blocking resistance. For example, it is applied to the surface of a building exterior or a ceramic building material. Although it can be used for topcoat (water-based paint) sealers and intermediate coats called top coats, it can be suitably used for top coats and sealers.

  When the aqueous resin composition of the present invention is used for a top coat, for example, one or more kinds of film forming aids, foam suppressors, pigments, thickeners, matting agents, etc. are appropriately added to the aqueous resin composition. By mixing, enamel paint, clear paint, etc. can be prepared, and these paints can be used for the top coat.

  The aqueous resin composition of the present invention is useful for sealers for inorganic building materials such as ceramic building materials. Examples of ceramic building materials include tiles and outer wall materials. Ceramic building materials are obtained by adding inorganic fillers, fibrous materials, etc. to hydraulic glue that is the raw material of inorganic hardened bodies, molding the resulting mixture, curing the resulting molded body, and curing it. can get. As an inorganic building material which comprises the exterior of a building, a flexible board, a calcium silicate board, a gypsum slag perlite board, a piece of wood cement board, a precast concrete board, an ALC board, a gypsum board etc. are mentioned, for example.

  In addition, when apply | coating the aqueous resin composition of this invention to the surface and back surface of building materials, the said building materials may be heated as needed from a viewpoint which manufactures the building materials which have a coating film on both surfaces efficiently. . When apply | coating the aqueous resin composition of this invention to building materials, a spray, a roller, a brush, a iron etc. can be used, for example. An overcoat material (water-based paint) may be applied to the surface of the building material in order to impart a desired design.

  EXAMPLES Next, although this invention is demonstrated further in detail based on an Example, this invention is not limited only to this Example. In the following examples, “part” means “part by weight” and “%” means “% by weight” unless otherwise specified.

Example 1
In a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer, and a reflux condenser, 810 parts of deionized water was charged. In a dropping funnel, 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 40 parts of 2-ethylhexyl acrylate, 210 parts of methyl methacrylate, cyclohexyl methacrylate A pre-emulsion for dropping consisting of 100 parts, 100 parts of styrene, 10 parts of methacrylic acid and 40 parts of ethylene glycol dimethacrylate is prepared, and 71 parts corresponding to 5% of the total amount of all polymerizable monomer components are added to the flask. The temperature was raised to 80 ° C. while gently blowing nitrogen gas, and 14 parts of a 3.5% aqueous solution of ammonium persulfate was added to initiate polymerization. Next, 43 parts of a 3.5% aqueous solution of ammonium persulfate and 30 parts of a 2.5% aqueous solution of sodium hydrogen sulfite, together with the balance of the pre-emulsion for dripping, were added dropwise over 120 minutes.

  After completion of the dropwise addition, the mixture is maintained at 80 ° C. for 60 minutes, followed by 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 2-ethylhexyl. Second stage pre-emulsion consisting of 200 parts of acrylate, 110 parts of methyl methacrylate, 100 parts of cyclohexyl methacrylate, 80 parts of styrene and 10 parts of acrylic acid, 43 parts of 3.5% aqueous ammonium persulfate solution and 30% aqueous 2.5% sodium bisulfite solution Were uniformly added dropwise over 120 minutes.

  After completion of the dropwise addition, the temperature was maintained at 80 ° C. for 120 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization. After cooling the obtained reaction liquid to room temperature, it filtered with a 300 mesh (JIS mesh, the same hereafter) wire mesh, the resin emulsion was prepared, and the obtained resin emulsion was used as an aqueous resin composition. The non-volatile content in the aqueous resin composition was 43%, and the average particle size of the emulsion particles was 150 nm.

Example 2
In a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer, and a reflux condenser, 810 parts of deionized water was charged. In a full funnel, 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 35 parts of 2-ethylhexyl acrylate, 175 parts of methyl methacrylate, cyclohexyl A dropping pre-emulsion comprising 100 parts of methacrylate, 100 parts of styrene, 10 parts of methacrylic acid, 40 parts of ethylene glycol dimethacrylate and 40 parts of trimethylolpropane trimethacrylate is prepared, of which 5% of the total amount of all polymerizable monomer components 71 parts corresponding to the above were added to the flask, the temperature was raised to 80 ° C. while gently blowing nitrogen gas, and 14 parts of a 3.5% aqueous solution of ammonium persulfate was added to initiate polymerization. Next, 43 parts of a 3.5% aqueous solution of ammonium persulfate and 30 parts of a 2.5% aqueous solution of sodium hydrogen sulfite, together with the balance of the pre-emulsion for dripping, were added dropwise over 120 minutes.

  After completion of the dropwise addition, the mixture is maintained at 80 ° C. for 60 minutes, followed by 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 2-ethylhexyl. Second stage pre-emulsion consisting of 200 parts of acrylate, 110 parts of methyl methacrylate, 100 parts of cyclohexyl methacrylate, 80 parts of styrene and 10 parts of acrylic acid, 43 parts of 3.5% aqueous ammonium persulfate solution and 30% aqueous 2.5% sodium bisulfite solution Were uniformly added dropwise over 120 minutes.

  After completion of the dropwise addition, the temperature was maintained at 80 ° C. for 120 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization. The obtained reaction solution was cooled to room temperature, and then filtered through a 300-mesh wire mesh to prepare a resin emulsion, and the obtained resin emulsion was used as an aqueous resin composition. The non-volatile content in the aqueous resin composition was 43%, and the average particle size of the emulsion particles was 150 nm.

Example 3
In a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer, and a reflux condenser, 810 parts of deionized water was charged. In a full funnel, 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 25 parts of 2-ethylhexyl acrylate, 105 parts of methyl methacrylate, cyclohexyl A pre-emulsion for dripping consisting of 100 parts of methacrylate, 100 parts of styrene, 10 parts of methacrylic acid, 60 parts of ethylene glycol dimethacrylate, 60 parts of trimethylolpropane trimethacrylate and 40 parts of dipentaerythritol tetraacrylate is prepared. 71 parts corresponding to 5% of the total amount of the monomer components were added into the flask, the temperature was raised to 80 ° C. while gently blowing nitrogen gas, and 14 parts of a 3.5% ammonium persulfate aqueous solution was added to initiate polymerization. Next, 43 parts of a 3.5% aqueous solution of ammonium persulfate and 30 parts of a 2.5% aqueous solution of sodium hydrogen sulfite, together with the balance of the pre-emulsion for dripping, were added dropwise over 120 minutes.

  After completion of the dropwise addition, the mixture is maintained at 80 ° C. for 60 minutes, followed by 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 2-ethylhexyl. Second stage pre-emulsion consisting of 300 parts of acrylate, 170 parts of cyclohexyl methacrylate, 10 parts of acrylic acid and 20 parts of γ-methacryloyloxypropyltrimethoxysilane, 43 parts of 3.5% aqueous ammonium persulfate solution and 2.5% sodium bisulfite 30 parts of the aqueous solution was uniformly dropped over 120 minutes.

  After completion of the dropwise addition, the temperature was maintained at 80 ° C. for 120 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization. The obtained reaction solution was cooled to room temperature, and then filtered through a 300-mesh wire mesh to prepare a resin emulsion, and the obtained resin emulsion was used as an aqueous resin composition. The non-volatile content in the aqueous resin composition was 43%, and the average particle size of the emulsion particles was 150 nm.

Example 4
In a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer, and a reflux condenser, 810 parts of deionized water was charged. In a full funnel, 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 300 parts of isobornyl methacrylate, 110 parts of cyclohexyl methacrylate, methacryl Prepare a pre-emulsion for dripping consisting of 10 parts of acid and 80 parts of trimethylolpropane trimethacrylate, of which 71 parts, which is 5% of the total amount of all polymerizable monomer components, are added into the flask and gently blown with nitrogen gas. While raising the temperature to 80 ° C., 14 parts of a 3.5% ammonium persulfate aqueous solution was added to initiate polymerization. Next, 43 parts of a 3.5% aqueous solution of ammonium persulfate and 30 parts of a 2.5% aqueous solution of sodium hydrogen sulfite, together with the balance of the pre-emulsion for dripping, were added dropwise over 120 minutes.

  After completion of the dropwise addition, the mixture is maintained at 80 ° C. for 60 minutes, followed by 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 2-ethylhexyl. Second stage pre-emulsion consisting of 200 parts of acrylate, 100 parts of methyl methacrylate, 100 parts of cyclohexyl methacrylate, 80 parts of styrene and 20 parts of acrylic acid, 43 parts of 3.5% aqueous ammonium persulfate solution and 30% aqueous 2.5% sodium bisulfite solution Were uniformly added dropwise over 120 minutes.

  After completion of the dropwise addition, the temperature was maintained at 80 ° C. for 120 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization. The obtained reaction solution was cooled to room temperature, and then filtered through a 300-mesh wire mesh to prepare a resin emulsion, and the obtained resin emulsion was used as an aqueous resin composition. The non-volatile content in the aqueous resin composition was 43%, and the average particle size of the emulsion particles was 150 nm.

Example 5
In a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer, and a reflux condenser, 810 parts of deionized water was charged. In a full funnel, 145 parts of deionized water, 60 parts of 25% aqueous solution of emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 200 parts of methyl methacrylate, 100 parts of cyclohexyl methacrylate, 100 parts of styrene , 10 parts of methacrylic acid, 80 parts of trimethylolpropane trimethacrylate and 10 parts of γ-methacryloyloxypropyltrimethoxysilane were prepared, of which 71 parts corresponding to 5% of the total amount of all polymerizable monomer components Was added to the flask, the temperature was raised to 80 ° C. while gently blowing nitrogen gas, and 14 parts of a 3.5% aqueous ammonium persulfate solution was added to initiate polymerization. Next, 43 parts of a 3.5% aqueous solution of ammonium persulfate and 30 parts of a 2.5% aqueous solution of sodium hydrogen sulfite, together with the balance of the pre-emulsion for dripping, were added dropwise over 120 minutes.

  After completion of the dropwise addition, the mixture is maintained at 80 ° C. for 60 minutes, followed by 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 2-ethylhexyl. Second stage pre-emulsion consisting of 200 parts of acrylate, 100 parts of methyl methacrylate, 100 parts of cyclohexyl methacrylate, 80 parts of styrene and 20 parts of acrylic acid, 43 parts of 3.5% aqueous ammonium persulfate solution and 30% aqueous 2.5% sodium bisulfite solution Were uniformly added dropwise over 120 minutes.

  After completion of the dropwise addition, the temperature was maintained at 80 ° C. for 120 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization. The obtained reaction solution was cooled to room temperature, and then filtered through a 300-mesh wire mesh to prepare a resin emulsion, and the obtained resin emulsion was used as an aqueous resin composition. The non-volatile content in the aqueous resin composition was 43%, and the average particle size of the emulsion particles was 150 nm.

Example 6
In a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer, and a reflux condenser, 810 parts of deionized water was charged. In a full funnel, 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 260 parts of 2-ethylhexyl acrylate, 150 parts of cyclohexyl methacrylate, methacrylic acid. Prepare a pre-emulsion for dripping consisting of 10 parts of acid and 80 parts of trimethylolpropane trimethacrylate, of which 71 parts, which is 5% of the total amount of all polymerizable monomer components, are added into the flask and gently blown with nitrogen gas. While raising the temperature to 80 ° C., 14 parts of a 3.5% ammonium persulfate aqueous solution was added to initiate polymerization. Next, 43 parts of a 3.5% aqueous solution of ammonium persulfate and 30 parts of a 2.5% aqueous solution of sodium hydrogen sulfite, together with the balance of the pre-emulsion for dripping, were added dropwise over 120 minutes.

  After completion of the dropwise addition, the mixture is maintained at 80 ° C. for 60 minutes, followed by 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 2-ethylhexyl. Second stage pre-emulsion consisting of 200 parts of acrylate, 100 parts of methyl methacrylate, 100 parts of cyclohexyl methacrylate, 80 parts of styrene and 20 parts of acrylic acid, 43 parts of 3.5% aqueous ammonium persulfate solution and 30% aqueous 2.5% sodium bisulfite solution Were uniformly added dropwise over 120 minutes.

  After completion of the dropwise addition, the temperature was maintained at 80 ° C. for 120 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization. The obtained reaction solution was cooled to room temperature, and then filtered through a 300-mesh wire mesh to prepare a resin emulsion, and the obtained resin emulsion was used as an aqueous resin composition. The non-volatile content in the aqueous resin composition was 43%, and the average particle size of the emulsion particles was 150 nm.

Example 7
In a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer, and a reflux condenser, 810 parts of deionized water was charged. In a full funnel, 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 300 parts of isobornyl methacrylate, 120 parts of cyclohexyl methacrylate, ethylene A pre-emulsion for dripping consisting of 40 parts of glycol dimethacrylate and 40 parts of dipentaerythritol tetraacrylate was prepared, of which 71 parts corresponding to 5% of the total amount of all polymerizable monomer components were added to the flask, and gently nitrogen gas was added. The temperature was raised to 80 ° C. while blowing, and 14 parts of a 3.5% ammonium persulfate aqueous solution was added to initiate polymerization. Next, 43 parts of a 3.5% aqueous solution of ammonium persulfate and 30 parts of a 2.5% aqueous solution of sodium hydrogen sulfite, together with the balance of the pre-emulsion for dripping, were added dropwise over 120 minutes.

  After completion of the dropwise addition, the mixture is maintained at 80 ° C. for 60 minutes, followed by 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 2-ethylhexyl. Second stage pre-emulsion consisting of 300 parts of acrylate, 170 parts of cyclohexyl methacrylate, 10 parts of acrylic acid and 20 parts of γ-methacryloyloxypropyltrimethoxysilane, 43 parts of 3.5% aqueous ammonium persulfate solution and 2.5% sodium bisulfite 30 parts of the aqueous solution was uniformly dropped over 120 minutes.

  After completion of the dropwise addition, the temperature was maintained at 80 ° C. for 120 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization. The obtained reaction solution was cooled to room temperature, and then filtered through a 300-mesh wire mesh to prepare a resin emulsion, and the obtained resin emulsion was used as an aqueous resin composition. The non-volatile content in the aqueous resin composition was 43%, and the average particle size of the emulsion particles was 150 nm.

Example 8
In a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer, and a reflux condenser, 810 parts of deionized water was charged. In a dropping funnel, 72 parts of deionized water, 30 parts of a 25% aqueous solution of emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 100 parts of 2-ethylhexyl acrylate, 145 parts of cyclohexyl methacrylate and methacrylic acid A pre-emulsion for dripping consisting of 5 parts was prepared, 71 parts corresponding to 5% of the total amount of all polymerizable monomer components were added into the flask, and the temperature was raised to 80 ° C. while gently blowing nitrogen gas. Polymerization was initiated by adding 14 parts of a 5% aqueous ammonium persulfate solution. Next, 21 parts of a 3.5% aqueous solution of ammonium persulfate and 15 parts of a 2.5% aqueous solution of sodium hydrogensulfite with the remainder of the pre-emulsion for dripping were dropped uniformly over 60 minutes.

  After completion of the dropwise addition, the mixture is maintained at 80 ° C. for 60 minutes. Subsequently, 73 parts of deionized water, 30 parts of a 25% aqueous solution of an emulsifier [manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 100 of methyl methacrylate Part, 50 parts of cyclohexyl methacrylate, 50 parts of styrene, 5 parts of methacrylic acid, 40 parts of trimethylolpropane trimethacrylate and 5 parts of γ-methacryloyloxypropyltrimethoxysilane, and 3.5% ammonium persulfate aqueous solution 22 parts and 15 parts of a 2.5% aqueous sodium hydrogen sulfite solution were uniformly added dropwise over 60 minutes.

  After completion of the dropwise addition, the mixture is maintained at 80 ° C. for 60 minutes, followed by 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 2-ethylhexyl. A third pre-emulsion comprising 200 parts of acrylate, 100 parts of methyl methacrylate, 100 parts of cyclohexyl methacrylate, 80 parts of styrene and 20 parts of acrylic acid, 43 parts of 3.5% aqueous ammonium persulfate solution and 30% aqueous 2.5% sodium bisulfite solution Were uniformly added dropwise over 120 minutes.

  After completion of the dropwise addition, the temperature was maintained at 80 ° C. for 120 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization. The obtained reaction solution was cooled to room temperature, and then filtered through a 300-mesh wire mesh to prepare a resin emulsion, and the obtained resin emulsion was used as an aqueous resin composition. The non-volatile content in the aqueous resin composition was 43%, and the average particle size of the emulsion particles was 150 nm.

Example 9
In a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer, and a reflux condenser, 810 parts of deionized water was charged. In a dropping funnel, 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 200 parts of methyl methacrylate, 100 parts of cyclohexyl methacrylate, 100 parts of styrene, A dropping pre-emulsion comprising 10 parts of methacrylic acid, 80 parts of trimethylolpropane trimethacrylate and 10 parts of γ-methacryloyloxypropyltrimethoxysilane was prepared, of which 71 parts corresponding to 5% of the total amount of all polymerizable monomer components were prepared. The mixture was added to the flask, heated to 80 ° C. while gently blowing nitrogen gas, and 14 parts of a 3.5% aqueous ammonium persulfate solution was added to initiate polymerization. Next, 43 parts of a 3.5% aqueous solution of ammonium persulfate and 30 parts of a 2.5% aqueous solution of sodium hydrogen sulfite, together with the balance of the pre-emulsion for dripping, were added dropwise over 120 minutes.

  After completion of dropping, the mixture is maintained at 80 ° C. for 60 minutes, and subsequently, 73 parts of deionized water, 30 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 2-ethylhexyl. A second pre-emulsion comprising 100 parts of acrylate, 50 parts of methyl methacrylate, 50 parts of cyclohexyl methacrylate, 40 parts of styrene and 10 parts of acrylic acid, 22 parts of 3.5% aqueous ammonium persulfate solution and 15% of 2.5% aqueous sodium hydrogen sulfite solution Were uniformly dropped over 60 minutes.

  After completion of the dropping, the temperature was maintained at 80 ° C. for 60 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia. Subsequently, 73 parts of deionized water, 30 parts of a 25% aqueous solution of an emulsifier [manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 115 parts of butyl acrylate, 115 parts of cyclohexyl methacrylate and 4-methacryloyloxy- A third pre-emulsion consisting of 20 parts of 2,2,6,6-tetramethylpiperidine, 22 parts of 3.5% aqueous ammonium persulfate solution and 15 parts of 2.5% aqueous sodium hydrogen sulfite solution are uniformly added dropwise over 60 minutes. did.

  After completion of dropping, the polymerization was completed by maintaining at 80 ° C. for 120 minutes. The obtained reaction solution was cooled to room temperature, and then filtered through a 300-mesh wire mesh to prepare a resin emulsion, and the obtained resin emulsion was used as an aqueous resin composition. The non-volatile content in the aqueous resin composition was 43%, and the average particle size of the emulsion particles was 150 nm.

Comparative Example 1
In a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer, and a reflux condenser, 810 parts of deionized water was charged. In a dropping funnel, 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 40 parts of 2-ethylhexyl acrylate, 235 parts of methyl methacrylate, cyclohexyl methacrylate A pre-emulsion for dripping consisting of 100 parts, 100 parts of styrene, 10 parts of methacrylic acid and 15 parts of ethylene glycol dimethacrylate is prepared, and 71 parts corresponding to 5% of the total amount of all polymerizable monomer components are added to the flask. The temperature was raised to 80 ° C. while gently blowing nitrogen gas, and 14 parts of a 3.5% aqueous solution of ammonium persulfate was added to initiate polymerization. Next, 43 parts of a 3.5% aqueous solution of ammonium persulfate and 30 parts of a 2.5% aqueous solution of sodium hydrogen sulfite, together with the balance of the pre-emulsion for dripping, were added dropwise over 120 minutes.

  After completion of the dropwise addition, the mixture is maintained at 80 ° C. for 60 minutes, followed by 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 2-ethylhexyl. Second stage pre-emulsion consisting of 200 parts of acrylate, 110 parts of methyl methacrylate, 100 parts of cyclohexyl methacrylate, 80 parts of styrene and 10 parts of acrylic acid, 43 parts of 3.5% aqueous ammonium persulfate solution and 30% aqueous 2.5% sodium bisulfite solution Were uniformly added dropwise over 120 minutes.

  After completion of the dropwise addition, the temperature was maintained at 80 ° C. for 120 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization. After cooling the obtained reaction liquid to room temperature, it filtered with a 300 mesh (JIS mesh, the same hereafter) wire mesh, the resin emulsion was prepared, and the obtained resin emulsion was used as an aqueous resin composition. The non-volatile content in the aqueous resin composition was 43%, and the average particle size of the emulsion particles was 150 nm.

Comparative Example 2
In a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer, and a reflux condenser, 810 parts of deionized water was charged. In a full funnel, 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 40 parts of 2-ethylhexyl acrylate, 210 parts of methyl methacrylate, cyclohexyl A dropping pre-emulsion comprising 100 parts of methacrylate, 100 parts of styrene, 10 parts of methacrylic acid, 20 parts of ethylene glycol dimethacrylate and 20 parts of trimethylolpropane trimethacrylate is prepared, of which 5% of the total amount of all polymerizable monomer components 71 parts corresponding to the above were added to the flask, the temperature was raised to 80 ° C. while gently blowing nitrogen gas, and 14 parts of a 3.5% aqueous solution of ammonium persulfate was added to initiate polymerization. Next, 43 parts of a 3.5% aqueous solution of ammonium persulfate and 30 parts of a 2.5% aqueous solution of sodium hydrogen sulfite, together with the balance of the pre-emulsion for dripping, were added dropwise over 120 minutes.

  After completion of the dropwise addition, the mixture is maintained at 80 ° C. for 60 minutes, followed by 145 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 2-ethylhexyl. Second stage pre-emulsion consisting of 80 parts of acrylate, 230 parts of methyl methacrylate, 100 parts of cyclohexyl methacrylate, 80 parts of styrene and 10 parts of acrylic acid, 43 parts of 3.5% aqueous ammonium persulfate and 30% aqueous 2.5% sodium bisulfite Were uniformly added dropwise over 120 minutes.

  After completion of the dropwise addition, the temperature was maintained at 80 ° C. for 120 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization. The obtained reaction solution was cooled to room temperature, and then filtered through a 300-mesh wire mesh to prepare a resin emulsion, and the obtained resin emulsion was used as an aqueous resin composition. The non-volatile content in the aqueous resin composition was 43%, and the average particle size of the emulsion particles was 150 nm.

Comparative Example 3
In a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer, and a reflux condenser, 810 parts of deionized water was charged. In a full funnel, 43.5 parts of deionized water, 18 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 12 parts of 2-ethylhexyl acrylate, 63 parts of methyl methacrylate , 30 parts of cyclohexyl methacrylate, 300 parts of styrene, 3 parts of methacrylic acid, and 12 parts of ethylene glycol dimethacrylate, of which 71 parts corresponding to 5% of the total amount of all polymerizable monomer components are contained in the flask. The temperature was raised to 80 ° C. while gently blowing nitrogen gas, and 14 parts of 3.5% aqueous ammonium persulfate solution was added to initiate polymerization. Next, 13 parts of a 3.5% aqueous ammonium persulfate solution and 9 parts of a 2.5% aqueous sodium hydrogensulfite solution together with the remainder of the pre-emulsion for dropping were added dropwise uniformly over 40 minutes.

  After completion of dropping, the mixture is maintained at 80 ° C. for 60 minutes, followed by 247 parts of deionized water, 102 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 2-ethylhexyl. 340 parts of acrylate, 187 parts of methyl methacrylate, 170 parts of cyclohexyl methacrylate, 136 parts of styrene and 17 parts of acrylic acid, 73 parts of 3.5% aqueous ammonium persulfate solution and 51% aqueous 2.5% sodium hydrogensulfite solution 51 Were uniformly dropped over 200 minutes.

  After completion of the dropwise addition, the temperature was maintained at 80 ° C. for 120 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization. The obtained reaction solution was cooled to room temperature, and then filtered through a 300-mesh wire mesh to prepare a resin emulsion, and the obtained resin emulsion was used as an aqueous resin composition. The non-volatile content in the aqueous resin composition was 43%, and the average particle size of the emulsion particles was 150 nm.

Comparative Example 4
In a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer, and a reflux condenser, 810 parts of deionized water was charged. In a full funnel, 247 parts of deionized water, 102 parts of a 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 68 parts of 2-ethylhexyl acrylate, 357 parts of methyl methacrylate, cyclohexyl A pre-emulsion for dripping consisting of 170 parts of methacrylate, 170 parts of styrene, 17 parts of methacrylic acid and 68 parts of trimethylolpropane trimethacrylate was prepared, of which 71 parts corresponding to 5% of the total amount of all polymerizable monomer components were placed in the flask. Then, the temperature was raised to 80 ° C. while gently blowing nitrogen gas, and 14 parts of a 3.5% aqueous solution of ammonium persulfate was added to initiate polymerization. Next, 73 parts of a 3.5% aqueous solution of ammonium persulfate and 51 parts of a 2.5% aqueous solution of sodium hydrogensulfite together with the remainder of the pre-emulsion for dropping were added dropwise uniformly over 200 minutes.

  After completion of dropping, the mixture is maintained at 80 ° C. for 60 minutes, followed by 43.5 parts of deionized water, 18 parts of 25% aqueous solution of an emulsifier [Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10], 2 -A second pre-emulsion consisting of 60 parts ethylhexyl acrylate, 33 parts methyl methacrylate, 30 parts cyclohexyl methacrylate, 24 parts styrene and 3 parts acrylic acid, 13 parts 3.5% aqueous ammonium persulfate solution and 2.5% sodium bisulfite. Nine parts of the aqueous solution was uniformly added dropwise over 40 minutes.

  After completion of the dropwise addition, the temperature was maintained at 80 ° C. for 120 minutes, and the pH was adjusted to 8 by adding 25% aqueous ammonia to complete the polymerization. The obtained reaction solution was cooled to room temperature, and then filtered through a 300-mesh wire mesh to prepare a resin emulsion, and the obtained resin emulsion was used as an aqueous resin composition. The non-volatile content in the aqueous resin composition was 43%, and the average particle size of the emulsion particles was 150 nm.

Table 1 shows the properties of the aqueous resin compositions obtained in each Example and each Comparative Example. In addition, the term of Table 1 means the following.
(Layer structure)
Number of layers constituting the emulsion particles [content of polyfunctional monomer in the inner layer]
Polyfunctional monomer content (%) in monomer component A used as a raw material for polymer (I) constituting the inner layer
[Content of monomer having Tg of 80 ° C. or higher in inner layer]
Content of monomer other than polyfunctional monomer having glass transition temperature of 80 ° C. or higher in monomer component other than polyfunctional monomer used for polymer (I) constituting the inner layer (%)
[Content of carboxyl group-containing monomer]
Content ratio (%) of carboxyl group-containing monomer in monomer component used for polymer (I) constituting the inner layer / monomer component used for polymer (II) constituting the outer layer Content of carboxyl group-containing monomer in (%)
[Tg of outer layer]
Glass transition temperature of polymer (II) constituting the outer layer (℃)
(Layer composition ratio)
Weight ratio of polymer (I) constituting the inner layer and polymer (II) constituting the outer layer [polymer (I) / polymer (II)]
[Total content of inner and outer layers]
Total content of polymer (I) and polymer (II) in emulsion particles (%)
[Inner layer Tg]
Glass transition temperature of polymer (I) constituting the inner layer (℃)
[MFT]
Minimum film-forming temperature of aqueous resin composition (℃)

While dispersing the aqueous resin composition obtained in each example or each comparative example with a homodisper at a rotational speed of 1500 min ⁻¹ , 2,2,4-trimethyl-1,3-pentanediol mono was used as a film forming aid. A mixed solution obtained by mixing isobutyrate [manufactured by Chisso Corporation, product number: CS-12] and butyl cellosolve at an equal weight is added, and the minimum film-forming temperature of the aqueous resin composition becomes 5 ° C. After adjusting as described above, the content of the non-volatile component was adjusted to 30% by adding dilution water and a foam suppressor [manufactured by San Nopco Co., Ltd., trade name: SN deformer 777].

A matting agent [manufactured by Nippon Shokubai Co., Ltd., trade name: Eposta MA1010] was added to the mixture at a ratio of 8.8 parts per 100 parts of the obtained mixture, and a Craves unit viscometer (manufactured by Brookfield, Thickener [manufactured by Nippon Shokubai Co., Ltd., trade name: AKRESET WR-503A] was added to the mixture so that the viscosity when measured at 25 ° C. using product number: KU-1) was 65 ± 1 KU. Then, this mixture was dispersed with a homodisper at a rotational speed of 1500 min ^{-1 for} 30 minutes to obtain a clear coating. The obtained clear paint was allowed to stand at room temperature for 1 day, and the following physical properties were examined. The results are shown in Table 4. In addition, in the physical properties, those having at least one “D” evaluation are determined to be unacceptable.

(1) Warm water whitening resistance Black acrylic plate obtained by molding methyl methacrylate by extrusion molding according to JIS K6717 (2006) [manufactured by Nippon Test Panel Co., Ltd., length: 75 mm, width: 150 mm, thickness 3 mm], the clear paint obtained above was applied with a 5 mil applicator and dried in a hot air dryer at 100 ° C. for 10 minutes to prepare a test plate.

After the obtained test plate was cured at 23 ° C. for 24 hours, the L value (L ₀ ) of the test plate was measured using a color difference meter [manufactured by Nippon Denshoku Industries Co., Ltd., trade name: spectral color difference meter SE-2000]. The test plate was further immersed in warm water adjusted to 60 ° C. for 120 hours, then pulled up from the warm water, wiped with Kim Towel (manufactured by Nippon Paper Crecia Co., Ltd.), and within 1 minute. The L value (L ₁ ) was measured with a color difference meter.

Next, the change value of the L value is expressed by
ΔL = (L ₁ ) − (L ₀ )
And evaluated based on the following evaluation criteria.
〔Evaluation criteria〕
A: ΔL is less than 2.0 B: ΔL is 2.0 or more and less than 4.0 C: ΔL is 4.0 or more and less than 6.0 D: ΔL is 6.0 or more

(2) Freezing and thawing resistance In accordance with JIS A5430 (2004), a slate plate (manufactured by Nippon Test Panel Co., Ltd., length: 70 mm, width: 150 mm, thickness: 6 mm) is coated with a solvent-based sealer [SK Kaken ( Co., Ltd., trade name: EX Sealer] was applied by air spray so that the dry weight was 20 g / m ² , dried at 23 ° C. for 24 hours, and then 5 mils of base coat paint having the following composition was applied. It apply | coated with the applicator and was dried for 10 minutes with a 100 degreeC hot-air dryer.

[Composition of paint for base coat]
・ Acrylic resin emulsion [made by Nippon Shokubai Co., Ltd., trade name: ACRYSET EX-41] 300 parts ・ White paste 135 parts Note that the white paste is a dispersant [trade name: DEMAL EP manufactured by Kao Corporation] 60 Part, dispersant [Daiichi Kogyo Seiyaku Co., Ltd., trade name: DISCOAT N-14] 50 parts, wetting agent [Kao Co., Ltd., trade name: Emulgen LS-106] 10 parts, propylene glycol 60 parts 210 parts of deionized water, titanium oxide [manufactured by Ishihara Sangyo Co., Ltd., product number: CR-95] 1000 parts, foam inhibitor [manufactured by San Nopco Co., Ltd., trade name: Nopco 8034L] and glass beads (diameter: 1 mm) was prepared by dispersing 60 parts with a homodisper at a rotational speed of 3000 min ^{−1 for} 60 minutes.
-30 parts of film forming aid (15 parts of butyl cellosolve, 15 parts of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate [manufactured by Chisso Corporation, product number: CS-12]) black paste [ Product made by Yokohama Kasei Co., Ltd., trade name: Unilant 88], 10 parts / foam suppressor [manufactured by San Nopco, trade name: Nopco 8034L] 1.5 parts

  Next, the clear paint obtained above was applied to a slate plate coated with the base coat paint with a 5 mil applicator and dried for 10 minutes with a hot air dryer at 100 ° C. to prepare a test plate.

The obtained test plate was cured in an atmosphere at 23 ° C. for 24 hours, and then the side and back surfaces of the test plate were sealed with a two-component curable solvent-based resin, and a freeze-thaw resistance test was performed with a freeze-thaw tester. . The freezing and thawing conditions at that time were air freezing (-20 ° C. for 2 hours) and water thawing (20 ° C. for 2 hours). Was observed visually using a magnifying glass, and the cycle until the test plate was cracked was measured, and freeze-thaw resistance was evaluated based on the following evaluation criteria.
〔Evaluation criteria〕
A: No crack at 400 cycles B: Crack occurred at 300 cycles or more and less than 400 cycles C: Crack occurred at 200 cycles or more and less than 300 cycles D: Crack occurred at less than 200 cycles

(3) Blocking resistance According to JIS R3202 (1996), the clear coating obtained above was applied to a float glass plate (manufactured by Nippon Test Panel Co., Ltd., 70 mm long, 150 mm wide, 2 mm thick) with a 5 mil applicator. The test plate was produced by applying and drying with a hot air dryer at 100 ° C. for 10 minutes.

Immediately move the obtained test plate into a hot air dryer at 60 ° C., adjust the temperature for 1 minute, and then apply gauze [manufactured by Hyoe Sanitary Materials Co., Ltd., Japanese Pharmacopoeia Gauze Type 1], float glass on the test plate. A board (manufactured by Nippon Test Panel Co., Ltd., 70 mm long, 150 mm wide, 2 mm thick) and a weight were loaded in this order and left at a temperature of 60 ° C. for 24 hours. At this time, the load was adjusted to be 280 g / cm ² .

Next, after the test plate was cooled to room temperature, the gauze on the test plate was slowly peeled off, the state of the coating film was visually observed, and evaluated based on the following evaluation criteria.
〔Evaluation criteria〕
A: No abnormality (no gauze marks)
B: Slight gauze trace C: Shallow gauze trace D: Deep gauze trace

(4) Comprehensive evaluation For each physical property, the evaluation of A is 35 points, the evaluation of B is 25 points, the evaluation of C is 15 points, and the evaluation of D is 0 points. Was done. The highest score for comprehensive evaluation is 105 points.

  From the results shown in Table 2, each of the aqueous resin compositions obtained in each example forms a coating film that is comprehensively excellent in hot water whitening resistance, freeze-thaw resistance, and blocking resistance. It can be seen that it is.

  The water-based resin composition of the present invention is expected to be used for sealers including top coat materials (water-based paints) called top coats that are coated on the surface of building exteriors and ceramic building materials, for example. Is.

Claims (7)

  An aqueous resin composition containing emulsion particles having an inner layer and an outer layer, wherein the inner layer is 5 to 50% by weight of a polyfunctional monomer and a monomer 50 to 95 copolymerizable with the polyfunctional monomer. The outer layer is formed of a polymer (II) having a glass transition temperature of 40 ° C. or lower, and is formed of a polymer (I) obtained by emulsion polymerization of a monomer component containing wt%. ) And polymer (II) in a weight ratio of [polymer (I) / polymer (II)] of 25/75 to 75/25, and the polymer (I) and polymer (II) in the emulsion particles A water-based resin composition having a total content of 50 to 100% by weight.   The aqueous resin composition according to claim 1, wherein the glass transition temperature of the polymer (I) is 70 ° C or higher.   3. The aqueous resin composition according to claim 1, wherein the monomer component used in the polymer (I) has a content of a monomer having a glass transition temperature of 80 ° C. or more of 80% by weight or more.   The aqueous resin composition according to claim 1, which has a minimum film-forming temperature of 60 ° C. or less.   The content of the carboxyl group-containing monomer in the monomer component used in the polymer (II) is higher than the content of the carboxyl group-containing monomer in the monomer component used in the polymer (I) Item 5. The aqueous resin composition according to any one of Items 1 to 4.   A water-based paint comprising the water-based resin composition according to claim 1.   A method for producing an aqueous resin composition containing emulsion particles having an inner layer and an outer layer, comprising 50 to 95% by weight of a polyfunctional monomer and 5 to 50% of a monomer copolymerizable with the polyfunctional monomer % Monomer component is emulsion-polymerized to form an inner layer composed of the obtained polymer (I), and then an outer layer composed of a polymer (II) having a glass transition temperature of 40 ° C. or lower is formed. In this case, the weight ratio of the polymer (I) to the polymer (II) [polymer (I) / polymer (II)] is adjusted to 25/75 to 75/25, and the polymer ( A method for producing an aqueous resin composition, wherein the content of I) and the polymer (II) is adjusted to 50 to 100% by weight.